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Saved by a cell phone

The search for a missing family in Oregon got a high-tech assist from the cellular phone system - which helped searchers focus in on the snowy mountain road where the mother and her two children were found on Monday. But like other aspects of this survival story, the saga of cell-phone salvation appears to have depended as much on a stroke of luck as on the technology itself.

The tale hasn't come to a happy ending yet: Yes, Kati Kim and her two daughters, 4-year-old Penelope and 7-month-old Sabine, were rescued after being stranded for nine days in their car. (It's fortunate that Kim was able to breast-feed both children to keep them going through the ordeal.) But James Kim, who set out to look for help two days before the rescue, is still missing.

The fact that anyone was rescued at all could well be due to the cell-phone angle: When Eric Fuqua, an engineer at Oregon-based Edge Wireless reviewed the company's records, he found that a "ping" from the Kims' cell phone had been detected at a signal tower near Glendale in southern Oregon at 1:30 a.m. PT Nov. 26. That particular tower could even determine the westerly region from which the signal came.

"We were actually able to identify that piece of the pie," Donnie Castleman, the president and chief executive officer of Edge Wireless, told me today.

The clue wasn't conclusive: The engineers could only sketch out an area roughly 26 miles on a side in Oregon's rugged Josephine County. A computer model helped narrow down the area further, based on the roads and terrain. All that helped concentrate the search - and eventually, a helicopter pilot spotted Kati Kim unfurling an umbrella as a distress signal.

Inspector Angela Martin, who led the San Francisco police's investigation, had high praise for Fuqua's detective work. "As far as I'm concerned, he's a hero to me," she told The Associated Press.

So does this mean you can always rely on your cell phone to let the authorities know where you are in the event of an emergency? Not really. But if you're heading down a dark and lonesome highway, you might want to try making a call or sending a text message every once in a while - just in case.

Even when you're not using your cell phone, the device periodically sends signals to cellular towers as you move from area to area. That "Here I Am" signal, or ping, is transmitted periodically as long as the phone is turned on, just so that the network knows how best to connect with your phone.

Theoretically, the network operators could look through their registry records to track a cell phone user on the basis of those pings. But in the Kims' case, that signal alone wouldn't have saved them. Castleman explained that there are just too many registry-related pings for his company to keep track of - and for that reason, the registry records aren't stored.

"This was really tied to the fact that a text message had been at least partially delivered," Castleman said. Edge Wireless did keep a record of the ping confirming message delivery, and that's what left a trace for the searchers to follow.

Cell phones - and cell-phone networks - are getting increasingly savvy about figuring out locations, in response to a mandate for enhanced 911 services, or E911.

"911 is a very early leader in location-based technology," said Doug Kroupa, an Illinois-based consultant who's working with AT&T on services related to emergency response and public safety.

In many areas, the network can figure out where you are by triangulating your signal from multiple cell towers. "You can generally figure out where you are to the length of a football field or two," Kroupa said.

And if you have a GPS-enabled phone, some cell networks can locate you spot-on.

Of course, there could be a downside to having your phone network know where you are. Privacy advocates worry that such services could turn your phone into a surveillance device, and earlier this year there was a huge controversy over the sale of ill-gotten phone records for all sorts of potentially nefarious purposes.

But when you're in a jam, the cell phone could turn into your best option for a lifeline, as detailed in this CNet report published today. With that in mind, here are a few tips from Castleman and Kroupa about road emergencies in general, and cell phones in particular:

Consider a GPS-enabled phone the next time you upgrade your cell service, Kroupa said.

When selecting a service provider, look for the one that provides the best signal strength and call quality, Castleman said.

Keep your phone fully charged, and if you're in a place where you don't need the cell phone, switch it off to conserve power for when you do need it. Castleman said he's sometimes guilty of not following these rules. "We tend to charge our batteries once a week," he said.

"Know the road that you're on," Kroupa said. That may mean taking note of the mile markers as you're rolling along - or at least being able to describe the terrain to a 911 operator if you're able to call in.

In that same vein, be conservative about where you're driving. Many folks have noted that the road where the Kims ended up is a nice shortcut in the summer, but virtually impassable in the winter. "That's a very, very remote part of the state," Castleman said. "They don't call it the Rogue River Wilderness Area for nothing."

"The biggest thing is, don't panic," Kroupa said. "More often than not, staying with your vehicle will help you be located much more frequently."

Update for 5 p.m. ET Dec. 6: The news came out just a while ago that James Kim was found dead in the mountains - a tragic end to the family's survival tale. My condolences go out to the family and all the searchers who worked so hard to save the Kims, including the techies. I happened to be sitting in the chair to talk about this case on MSNBC when the news broke ... you can check out the cable-TV clips here (before we heard about James Kim's death) and here (afterward).